persistence of weight loss and acquired behaviors 2 y after stopping a 2 y calorie restriction intervention

ABSTRACT Background: Calorie restriction (CR) influences aging processes and extends average and maximal life spans. The CALERIE 2 (Comprehensive Assessment of Long-Term Effects of Reducing Intake of Energy Phase 2) study was the first randomized clinical trial to examine the metabolic and psychological effects of CR in nonobese humans. Objective: We conducted a 2-y follow-up study of adults who un- derwent 2 y of CR or ad libitum (control) consumption and deter- mined whether weight loss and acquired behaviors persisted after the study ended when participants determined their own lifestyle behaviors. Design: In this prospective, longitudinal study, we assessed differ- ences in weight, body composition, psychological function, and energy expenditure in 39 nonobese [body mass index (in kg/m2): 22–28] men and women (25% CR: n = 24; control: n = 15) 12 and 24 mo after they completed the CALERIE 2 study at Pennington Biomedical. Results: Of 39 participants who were in the follow-up study, 29 subjects (CR: n = 18; control: n = 11) completed all visits at follow- up months 12 and 24. After the CR intervention, a mean 6 SEM weight loss of 9.0 6 0.6 kg was observed in the CR group, in which only 54% of the weight was regained 2 y later. Despite such a regain, weight, the percentage of body fat, and fat mass remained significantly reduced from baseline throughout follow-up and re- mained significantly less than in the control group (P , 0.05). At follow-up, the CR group retained higher degrees of dietary re- straint and avoidance of certain foods. Conclusion: After a 2-y intensive CR intervention, w50% of CR-induced weight loss was maintained 2 y later, which was prob- ably the result of lasting effects on acquired behaviors and die- tary restraint. This trial was registered at clinicaltrials.gov as NCT00943215. Am J Clin Nutr 2017;105:928–35.